scsi: ufs: core: Remove ufshcd_map_desc_id_to_length()

There shouldn't be any restriction of the descriptor size (not the
descriptor id for that matter) up to QUERY_DESC_MAX_SIZE.  According to the
spec, the caller can use any descriptor size, and it is up to the device to
return the actual size.  Therefore there shouldn't be any sizes hardcoded
in the kernel, nor any need to cache it, hence the
ufshcd_map_desc_id_to_length() function is redundant. Always read the
descriptors with QUERY_DESC_MAX_SIZE size.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Suggested-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Arthur Simchaev <Arthur.Simchaev@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufs_bsg.c

@@ -16,7 +16,6 @@ static int ufs_bsg_get_query_desc_size(struct ufs_hba *hba, int *desc_len,
 				       struct utp_upiu_query *qr)
 {
 	int desc_size = be16_to_cpu(qr->length);
-	int desc_id = qr->idn;
 
 	if (desc_size <= 0)
 		return -EINVAL;

drivers/ufs/core/ufshcd.c

@@ -3395,12 +3395,6 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
 	if (desc_id >= QUERY_DESC_IDN_MAX || !param_size)
 		return -EINVAL;
 
-	if (param_offset >= buff_len) {
-		dev_err(hba->dev, "%s: Invalid offset 0x%x in descriptor IDN 0x%x, length 0x%x\n",
-			__func__, param_offset, desc_id, buff_len);
-		return -EINVAL;
-	}
-
 	/* Check whether we need temp memory */
 	if (param_offset != 0 || param_size < buff_len) {
 		desc_buf = kzalloc(buff_len, GFP_KERNEL);
@@ -3415,13 +3409,21 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
 	ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
 					    desc_id, desc_index, 0,
 					    desc_buf, &buff_len);
-
 	if (ret) {
 		dev_err(hba->dev, "%s: Failed reading descriptor. desc_id %d, desc_index %d, param_offset %d, ret %d\n",
 			__func__, desc_id, desc_index, param_offset, ret);
 		goto out;
 	}
 
+	/* Update descriptor length */
+	buff_len = desc_buf[QUERY_DESC_LENGTH_OFFSET];
+
+	if (param_offset >= buff_len) {
+		dev_err(hba->dev, "%s: Invalid offset 0x%x in descriptor IDN 0x%x, length 0x%x\n",
+			__func__, param_offset, desc_id, buff_len);
+		return -EINVAL;
+	}
+
 	/* Sanity check */
 	if (desc_buf[QUERY_DESC_DESC_TYPE_OFFSET] != desc_id) {
 		dev_err(hba->dev, "%s: invalid desc_id %d in descriptor header\n",
@@ -3430,9 +3432,6 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
 		goto out;
 	}
 
-	/* Update descriptor length */
-	buff_len = desc_buf[QUERY_DESC_LENGTH_OFFSET];
-
 	if (is_kmalloc) {
 		/* Make sure we don't copy more data than available */
 		if (param_offset >= buff_len)